Augmented superior rectus muscle transposition in management of defective ocular abduction.

BACKGROUND: Superior rectus muscle transposition (SRT) is one of the proposed transposition techniques in the management of defective ocular abduction secondary to chronic sixth nerve palsy and esotropic Duane retraction syndrome (Eso-DRS). The aim of the current study is to report the outcomes of augmented SRT in treatment of Eso-DRS and chronic sixth nerve palsy. METHODS: a retrospective review of medical records of patients with Eso-DRS and complete chronic sixth nerve palsy who were treated by augmented full tendon SRT combined with medial rectus recession (MRc) when intraoperative forced duction test yielded a significant contracture. Effect on primary position esotropia (ET), abnormal head posture (AHP), limitation of ocular ductions as well as complications were reported and analyzed. RESULTS: a total of 21 patients were identified: 10 patients with 6th nerve palsy and 11 patients with Eso-DRS. In both groups, SRT was combined with ipsilateral MRc in 18 cases. ET, AHP and limited abduction were improved by means of 33.8PD, 26.5°, and 2.6 units in 6th nerve palsy group and by 31.1PD, 28.6°, and 2 units in Eso-DRS group respectively. Surgical success which was defined as within 10 PD of horizontal orthotropia and within 4 PD of vertical orthotropia was achieved in 15 cases (71.4%). Significant induced hypertropia of more than 4 PD was reported in 3 patients (30%) and in 2 patients (18%) in both groups, respectively. CONCLUSION: augmented SRT with or without MRc is an effective tool for management of ET, AHP and limited abduction secondary to sixth nerve palsy and Eso-DRS. However, this form of augmented superior rectus muscle transposition could result in high rates of induced vertical deviation.

Effect of lateral rectus muscle resection on abduction in Duane retraction syndrome type 1.

PURPOSE: To assess the effect of lateral rectus muscle resection on abduction in Duane retraction syndrome (DRS) type 1. METHODS: The medical records of patients with DRS type 1 were reviewed retrospectively. Fifteen patients who underwent lateral rectus resection were included. Prism and cover test and the Krimsky test were used to detect deviations. Ocular ductions, abnormal head position (AHP), and globe retraction were recorded. RESULTS: Nine (60.0%) patients were female. The mean age was 13.1 ± 2.3 (range, 2-34) years. Left eyes were included in ten (66.7%) patients. Mean follow-up time was 37.6 ± 16.6 (range, 6-70) months. All patients had AHP, 13 patients had mild globe retraction, and 2 patients had no globe retraction preoperatively. Mean lateral rectus resection was 3.1 ± 0.7 (range, 2.0-4.5) mm, and the mean medial rectus recession was 4.4 ± 0.6 (range, 3.0-5.0) mm. The mean preoperative deviation decreased from 23.3 ± 6.9 (range, 14-35) prism diopters (pd) to 2.2 ± 4.1 (range, 0-10) pd at near, and from 23.6 ± 7.1 (range, 14-35) pd to 1.8 ± 3.5 (range, 0-10) pd at distance, at 6 months postoperatively (p = 0.01). The mean limitation in abduction decreased from - 3.2 ± 0.9 to - 1.3 ± 1.1 postoperatively (p < 0.001). AHP resolved in all patients. There was not a limitation in adduction or a worsening of globe retraction in any patient. CONCLUSION: Lateral rectus resection can be used to improve abduction in patients with DRS type 1 who have mild globe retraction. We assume that this procedure has no worsening effect on globe retraction in appropriate cases.

[Improvement of surgical treatment of Duane syndrome in children]. / Sovershenstvovanie khirurgicheskogo lecheniya sindroma Dueina u detei.

PURPOSE: To analyze the use of bifurcation of the lateral rectus muscle (LRM) in the surgical treatment of Duane syndrome (DS) in children. MATERIAL AND METHODS: The analysis of surgical treatment involved 12 children with paralytic strabismus at the age of 8 to 17. The following research methods were conducted for all patients: the study of eye motility in different directions of gaze, the study of eyes position and the degree of deviation in different positions of gaze, the Bielschowsky test, the Park's three-step test, determination of the nature of torticollis, the forcing test - intraoperative forceps test, multislice computed tomography (MSCT) of the head and orbit, ultrasonography of the oculomotor muscles. All study children underwent bifurcation (Y-cleavage procedure) of LRM with recession in exo-DS in 17% of cases, without recession in eso-DS - 83% of cases, respectively. RESULTS: In all operated patients with Duane syndrome, the direction of LRM was compensated (downshoot and upshoot were eliminated). In a direct gaze, the correct position was achieved in 10 (83%) cases, in 2 (17%) the residual angle of up to 10 PD remained, and torticollis was eliminated in 9 (75%) patients. CONCLUSION: The method of LRM bifurcation - the procedure of dividing the muscle into two portions and changing its primary localization, accompanied by abnormalities (presence of deviation, retraction, anomalous vertical movements, limited ocular motility, etc.), - helps compensate for them, and provides cosmetic as well as functional improvement.

Adhesion after Y-split procedure can affect its mechanism for treating overshoots in Duane's syndrome.

PURPOSE: To investigate the extent of adhesion and changes in the Y configuration after the Y-split procedure, compared with the posterior fixation suture. METHODS: Twelve New Zealand white rabbits were included in the study. The 10-mm Y-split procedure was performed in the superior rectus muscle (SR) of one eye, and the 10-mm posterior fixation suture was made in the SR of the other eye. Six weeks after surgery, the Y arm lengths and lengths of adherence to the sclera were measured. If the adhesion involved the whole Y arm, the distance between the original SR insertion and most proximal part of the adhered SR was measured. In the eyes with posterior fixation suture, the distance between the SR insertion and most proximal part of the adhered SR was evaluated. RESULTS: The average nasal and temporal Y arm lengths were 6.37 ± 0.65 and 6.54 ± 0.63 mm, respectively, a significant decrease from those measured immediately after surgery (P = 0.002 and 0.002, respectively). Adhesions involved the entire Y arms in 11 of 12 SRs (91.7%), with an average adhesion length of 7.01 ± 1.04 mm. In SRs with posterior fixation sutures, the average adhesion was 9.18 ± 0.62 mm from the insertion, which was only 2.17 mm posterior to proximal portion of adhesion in Y-split SR (P < 0.001). CONCLUSIONS: Healing process reduces the Y arm length. Adhesion may involve the entire Y arm and could weaken or alter the therapeutic mechanism after the Y-split procedure.

Oculo-Auriculo-Fronto-Nasal Syndrome With Duane Retraction Syndrome and Dysplastic Bony Structure in the Midline of Nose.

Oculo-auriculo-fronto-nasal syndrome (OAFNS) is a rare anomaly characterized by features overlapping those of frontonasal dysplasia (FND) and the oculo-auriculo-vertebral spectrum (OAVS). The FND features malformation of frontonasal process-derived structures, characterized by anomalies in the central portion of the face. The OAVS is characterized by developmental anomalies of the first and second pharyngeal arches. The OAFNS is a condition with clinical features of both FND and OAVS.Here, the authors present the case of a male with OAFNS who not only exhibited typical OAFNS symptoms but also a dysplastic bony structure that bridged the anterior nasal spine and inferior nasal bones, and unilateral type 3 Duane retraction syndrome (absence of right-eye abduction). Abnormal nasal bones are characteristic of OAFNS; such abnormalities are absent from FND and OAVS. The authors reduced the dysplastic nasal bony structure via open external rhinoplasty, followed by lateral nasal osteotomy when he was 16 years of age. The nasal dorsum appeared natural after surgery and he was satisfied with the result.

Augmented superior rectus transposition procedure in Duane retraction syndrome compared with sixth nerve palsy.

PURPOSE: Superior rectus transposition (SRT) with medial rectus recession has been used for the treatment of sixth nerve palsy and esotropic Duane retraction syndrome (DRS). The purpose of this study was to compare the results of augmented SRT (with scleral fixation) without medial rectus recession in DRS and sixth nerve palsy. METHODS: Patients with unilateral esotropic DRS (DRS group) and sixth nerve palsy were included in this prospective, comparative study and underwent SRT. Preoperative forced duction testing was negative or slightly positive in both groups. Prospective measurements were compared between the two groups. RESULTS: There were 11 patients in the DRS group and 11 patients in the sixth nerve palsy group. The mean preoperative esotropia decreased from 20.9 ± 6.0 prism diopter (PD) at far to 13.2 ± 5.8 PD in the DRS group (P = 0.003). The same measurement improved from 28.0 ± 8.5 PD to 8.4 ± 7.3 PD in the sixth nerve palsy group (P = 0.003). In the sixth nerve palsy group, the improvement in primary gaze esotropia and abnormal head posture was more than the DRS group (Both P < 0.001).The average dose effect for SRT was 7.8 ± 2.2 PD in the DRS group and 19.2 ± 4.6 PD in the sixth nerve palsy group. Although objective intorsion was significantly induced after SRT, subjective torsion was not significant after surgery in both groups. CONCLUSION: SRT appears to be more effective in improving primary gaze deviation and head posture in sixth nerve palsy compared with DRS. Subjective torsional and vertical diplopia were rare in both groups.

Lateral rectus muscle recession for intermittent exotropia with anomalous head position in type 1 Duane's retraction syndrome.

BACKGROUND: We questioned how to treat for intermittent exotropia in type 1 Duane's retraction syndrome (DRS). To avoid secondary abduction deficit and late overcorrection on the affected eye following ipsilateral lateral rectus (LR) recession, we performed less correction of the lateral rectus (LR) recession to correct exodeviation and anomalous head position (AHP). We report the surgical outcomes of LR recession in patients with unilateral type 1 DRS. METHODS: Four patients who underwent less correction of LR recession in the affected eye to correct intermittent exotropia and AHP to the contralateral side in type 1 DRS were enrolled. Data on preoperative and postoperative angle of exodeviation, degree of AHP, ocular motility, global retraction, palpebral fissure change, and complications were retrospectively obtained. Success was defined as postoperative deviation within 8 prism diopters (PD) and AHP < 5°. RESULTS: The preoperative angles of exodeviation and AHP were significantly improved after LR recession. The median grade of abduction limitation was improved from - 1.3 to - 0.8 postoperatively. Final median value of deviation was orthotropia in the primary position of the eye with the normal motility. All patients had successful outcomes without overcorrection or further abduction limitation in DRS eyes. CONCLUSIONS: Less correction of ipsilateral LR recession may be useful for correcting intermittent exotropia and AHP in patients with type 1 DRS.

Postoperative full abduction in a patient of Duane retraction syndrome without an abducens nerve: a case report.

BACKGROUND: Duane retraction syndrome (DRS) consists of abduction deficit, globe retraction and upshoots or downshoots with adduction. The abducens nerve on the affected side is absent in type 1 DRS. After bilateral medial rectus muscle recession in unilateral type 1 DRS may improve the abduction limitation, but still more than -3 limitation remains. CASE PRESENTATION: A 6-month-old boy presented with esotropia which had been noticed in early infancy. He showed limited abduction, fissure narrowing on attempted adduction and a small upshoot OS. Left abducens nerve was not identified on magnetic resonance imaging compatible with Duane retraction syndrome type 1. He showed full abduction after bilateral medial rectus recession of 6.0 mm at the age of 9 months, and remained orthotropia with full abduction OU 2 years postoperatively. He is my only patient with Duane retraction syndrome who showed full abduction after bilateral medial rectus recession. CONCLUSIONS: A patient with the type 1 Duane retraction syndrome rarely may show full abduction after bilateral medial rectus recession mimicking infantile esotropia.

Aligning Strabismus Surgery with Duane Syndrome.

Initial consideration for surgical intervention tends to be resection and recession of affected muscles for strabismus. Resection of eye muscles in patients with Duane syndrome is often avoided because this increases retraction, thus decreasing eye movement and resulting binocular field of vision. Recession is the mainstay of surgical treatment in Duane syndrome to achieve straight eye alignment, increased binocular vision, and decreased head turn.

Stability of Y-splitting procedure combined with hang-back recession of the rectus muscle in rabbit eyes.

BACKGROUND: The Y-splitting procedure has been used both to treat up-shoots and down-shoots in Duane syndrome, and as a substitute for posterior fixation suture. The Y-split is often performed in conjunction with a hang-back recession when a large amount of recession or an adjustable suture is necessary. Herein, we evaluated the stability of Y-splitting hang-back recession in the rectus muscle. METHODS: Under general anesthesia, a 5-mm hang-back recession of the superior rectus muscle (SR) with Y-splitting was performed in ten eyes from ten rabbits (hang-back group). A conventional recession was performed in the SR of the fellow eye (control group). Six weeks after the procedure, the distance between the original insertion and the recessed SR (recession amount) and the width between the nasal and temporal halves of the SR were measured. These values were compared to the measurements taken at the time of surgery. RESULTS: The hang-back group had a significantly larger forward displacement than the control group (P < 0.001 for both the nasal and temporal halves). The width change between the nasal and temporal halves was also significantly larger in the hang-back group (4.94 ± 1.32 mm) than in the control group (1.14 ± 0.60 mm, P < 0.001). Additionally, the Y-configuration appeared to be more collapsed in the hang-back group than in the control group. CONCLUSION: Y-splitting of the rectus muscle may be unstable when it is combined with a hang-back recession. Surgeons should consider this possibility when performing Y-splitting procedures.

[Medial rectus tendon elongation with bovine pericardium for type 1 Duane's retraction syndrome]. / M.-rectus-internus-Sehnenverlängerung mit bovinem Perikard bei Duane-Retraktionssyndrom Typ 1.

BACKGROUND: Some patients with esotropic Duane's retraction syndrome (type 1) adopt a head turn to gain binocular vision. For some patients recession of the ipsilateral medial rectus muscle is not sufficient to eliminate head turn and squint angle. Surgery with tendon elongation allows the correction of larger angles and maintains a sufficient arc of contact. We report our results and experience. METHODS: We retrospectively reviewed the medical records of 10 patients with unilateral, esotropic Duane syndrome type 1 who had tendon elongation with bovine pericardium to correct a head turn or squint angle. Two patients had primary surgery with tendon elongation due to preoperative excessive angles, eight patients had tendon elongations as secondary procedures. Nine of the patients had their follow-up examination at least six weeks after surgery. RESULTS: The median preoperative angle of squint in primary position was + 27.5 pdpt, the median postoperative angle + 0 pdpt. The median dose effect relation for secondary interventions was 2.4 pdpt reduction of squint angle/mm surgery, for one patient with primary surgery and long-term follow-up 2.75 pdpt/mm. The median, preoperative head turn of seven patients with preoperative binocular functions was 20°. Postoperatively, six patients with long-term follow-up showed a median head turn of 0°. The median dose-effect relation was 3.3° reduction of head turn/mm surgery. All nine patients with long-term follow-up had a maximal head turn of 10°, six of the patients had no persisting head turn. Binocular functions were stable or better than preoperatively. CONCLUSIONS: For patients with retraction syndrome type 1, tendon elongation of the medial rectus muscle using Tutopatch® is a good option for secondary interventions or excessive preoperative squint angle or head turn.

Duane's syndrome: surgical outcome and non ophthalmologic associations.

BACKGROUND: Duane retraction syndrome (DRS) is the most common of the ocular congenital cranial dysinnervation disorders .This study evaluates the types of Duane syndrome and its management in patients presenting to the paediatric and strabismus unit of a tertiary care eye hospital. METHODS: This case series study involved 41 patients diagnosed with Duane syndrome between January 2007 and December 2009. History of presenting complaints, past treatment and family history were recorded. Ocular examination and orthoptic assessment was carried out RESULTS: Forty one patients were included in this case series study. It involved 10 right eyes, 27 left eyes and both eyes of 4 patients. There were 26 females and 15 males. Type-1 Duane syndrome was present in 28 (68.3%), type 2 in 8 (19.5%), Type-3 in 4 (9.8%) and type-4 with synergistic divergence was present in 1 (2.4%) patient. Comorbidity was present in 6(14.6%) patients. Surgery was carried out in 26 (63.4%) patients either for  abnormal head posturing or significant upshoots or down shoots. Upshoots noted in 21 eyes, were completely or partially resolved in 15 cases. Among 4 patients with down shoots on adduction, complete resolution was seen in 1. The pre and post-operative measurements of horizontal deviation showed statistically significant difference in Duane type-1 and 2, where as in Duane type-3 it was not significant. One patient with type-4 Duane did not undergo surgery. CONCLUSIONS: Recession of the horizontal recti is more effective in treating the upshoot or down shoot associated with DRS as compared to recession and y-split of the horizontal muscle.

Iatrogenic Pseudo-Duane Retraction Syndrome Following Orbitozygomatic Craniotomy.

Restrictive strabismus is a known complication of orbitozygomatic craniotomy. However, a pseudo-Duane syndrome has not been described following this procedure. The authors describe a 58-year-old woman who after craniotomy developed incomitant left exotropia with an adduction deficit; the globe retracted and palpebral fissure narrowed with attempted ocular adduction. [J Pediatr Ophthalmol Strabismus. 2024;61(1):e7-e10.].

Surgical management of enophthalmos in Duane syndrome.

Duane syndrome is a congenital disorder of eye movement characterized by partial or absent development of the sixth cranial nerve nucleus and/or the sixth nerve itself. Patients often undergo procedures, both surgical and nonsurgical, to correct ocular misalignment and improve the resulting visual problems. We present a case report of a 49-year-old woman with left-sided Duane syndrome who underwent aesthetic surgical correction of enophthalmos.

[Using the superficial temporal fascia flap in orbital surgery]. / Utilisation du lambeau de fascia temporalis superficialis en chirurgie orbitaire.

The superficial temporal fascia flap gives a fine malleable well vascularized tissue and can be used as a pedicled or a free flap to cover large areas of loss of substance. Its dissection needs a period of training. Its use in orbital surgery is rare. However when it is about an anophthalmic socket following radiotherapy with orbital retraction syndrome, it provides tissue of good quality. This could allow later reconstruction by mucous grafts. When used on cavities of exenteration it allows fast re-epithelialisation even post-radiotherapy, while allowing the monitoring of the cavity and in particular the early detection of any tumor recurrence. Its use is advantageous in unfavorable conditions especially after radiotherapy.

Modified Nishida Procedure Combined with Lateral Rectus Disabling for Duane Retraction Syndrome.

Duane retraction syndrome (DRS) is a complex congenital cranial dysinnervation disorder. The choice of surgical procedure in esotropic-DRS depends upon several factors that include: the amount of esotropia in the primary position, the presence and severity of palpebral fissure narrowing, globe retraction, presence of medial rectus muscle (MR) contracture, the likelihood of improving abduction, age of the patient, and the presence of binocularity and stereopsis. In the presence of MR contracture, MR recession is performed either alone (unilaterally or bilaterally) or in conjunction with Y splitting plus recession of the lateral rectus muscle (LR) for reducing globe retraction. MR recession, with or without adjustable sutures, may be simultaneously combined with partial thickness vertical rectus muscle transposition (VRT) or with superior rectus muscle transposition (SRT). We describe a novel combination of surgical procedures in the management of esotropic-DRS in two patients. In our first patient, following an initial MR recession combined with LR disinsertion and periosteal fixation (LRDAPF), a modified Nishida procedure was performed. In our second patient following a prior simultaneous MR recession and LR Y splitting with recession, we combined periosteal fixation of the LR with a modified Nishida procedure of the vertical rectus muscles.

Modified Nishida's procedure for esotropia in Duane syndrome associated with Goldenhar syndrome.

Modified Nishida's procedure (no split, no tenotomy transposition) has been recently described as an effective surgery for monocular elevation deficiency and for traumatic rupture of the inferior rectus muscle. We report the modified Nishida's procedure combined with medial rectus muscle recession for the treatment of esotropia in unilateral Duane syndrome associated with Goldenhar syndrome. Following the surgery and over a 1-year follow-up period, the patient was orthophoric at distance and near, abduction improved, and the abnormal head position resolved.

[Recession of both horizontal rectus muscles in Duane Retraction Syndrome with significant globe retraction].

OBJECTIVE: To evaluate the effect of Recession of both horizontal rectus muscles in Duane Retraction Syndrome with significant globe retraction. METHODS: Sixteen cases with DRS were summarized retrospectively. All patients had undergone surgery with recession of both horizontal rectus muscles. All clinical records, including sex, age, types of DRS, clinical features, surgical methods and clinical outcomes were analyzed. All patients were followed up for 3 months to 1 year. RESULTS: Fifteen cases had only monocular involvement while one had both eyes. The number of type I DRS was 3 cases, 1 case was esotropia while others were orthotropic in primary position. Type III DRS was observed 13 cases. Esotropia was seen in 6 cases (7 eyes), exotropia of 1 cases and orthotropic in primary position of 6 cases. 10 cases exhibited marked face turn. An upshoot or downshoot and variable severity of retraction of globe were found in all patients on attempt adduction of the affected eye. All patients had undergone surgery with recession of both horizontal rectus muscles. The medical rectus muscles were recessed from 5 mm to 7 mm and lateral rectus muscles 3 mm to 9 mm simultaneously, which was based on the amount of primary position deviation. Among these 2 cases were combined with Y-splitting of lateral rectus muscle. After surgery, all patients were orthotropic in primary position. Their symptom of unacceptable abnormal head position, significant globe retraction, noticeable narrowing of the palpebral fissure and significant upshoot or downshoot were ameliorated or disappeared. Especially the recession of lateral rectus muscle in addition to Y-splitting combining with the simultaneous medial rectus recession resulted in further amelioration of globe retraction in addition to upshoot and downshoot. CONCLUSION: Recession of both horizontal rectus muscles is effective in the treatment of significant globe retraction in Duane syndrome. Type III DRS with significant globe retraction but has no marked deviation and face turn can adopt this method to ameliorate their aspect. The method of lateral rectus muscle in addition to Y-splitting plays an important role in the treatment of upshoot and downshoot.

Hummelsheim procedure combined with medial rectus recession in complete sixth nerve palsy and esotropic Duane Retraction Syndrome.

PURPOSE: To evaluate the effect of half tendon vertical rectus muscle transposition (HVRT) combined with medial rectus muscle recession (MRrec) in complete sixth nerve palsy (CSNP) and esotropic Duane Retraction Syndrome (eDRS). METHODS: A retrospective study of patients with unilateral CSNP or eDRS who underwent HVRT combined with medial rectus recession over the course of 18 years. The patients with previous strabismus surgery and follow up less than 3 months were excluded. Overcorrection was defined as any amount of exotropia, and undercorrection was defined as residual esotropia of ⩾10 prism diopter (PD). RESULTS: A total of 39 patients were enrolled including 22 CSNP and 17 eDRS patients. Esotropia improved from 45.8 ± 22 and 22.5 ± 6.4 PD to 0.8 ± 2.5 and 0.3 ± 1 PD in CSNP group and eDRS group respectively. The angle of face turn improved from 34.3 ± 8.4° and 26.5 ± 9° to 0.6 ± 2.4° and 0.8 ± 1.6° in the CSNP group and eDRS group respectively. Abduction limitation improved from -4.5 ± 0.5 and -4 ± 0 units to -2.9 ± 0.5 and -2.7 ± 0.5 units in CSNP group and eDRS group respectively. No patient developed a new vertical deviation. An overcorrection occurred in one patient of the eDRS group who improved after botulinum toxin injection in the ipsilateral lateral rectus muscle. Undercorrection was seen in two patients. CONCLUSION: HVRT combined with MRrec is an effective procedure to improve esotropia, face turn, and abduction limitation in CSNP and eDRS.

Clinical characteristics and surgical approach in Duane retraction syndrome: a study of 691 patients.

PURPOSE: To evaluate the clinical findings of different types of Duane retraction syndrome (DRS). STUDY DESIGN: Retrospective. METHODS: This study was performed on 691 patients with DRS who underwent surgery. Clinical examinations included laterality, abnormal head posture (AHP), corrected distance visual acuity (CDVA), refractive error, amblyopia, deviation, overshoots, and type of surgery. RESULTS: The mean age of patients with DRS was 16.7 ± 12.5 (range 1.0-73) years. The patients included 396 (57.3%) women and 295 (42.7%) men (P < 0.001). DRS type I, was observed in 429 (62.1%), II in 168 (24.3%), III in 88 (12.7%) and IV in 6 (0.9%) patients. Unilateral DRS was observed OS in 628 (90.9%) [471 (%78.9) and OD in 157 (21.1%) eyes (P < 0.001)]. O ther clinical findings were AHP (n = 522, 78.1%), overshoot (n = 236, 34.2%) and amblyopia (n = 118, 17.1%). The prevalence of overshoot in types I, II, and III was 17.5% (75/429), 60.7% (102/168) and 64.8% (57/88), respectively (P < 0.001). The prevalence of amblyopia was significantly lower in patients with AHP (80/522, 15.3%) compared to patients with normal head posture (38/169, 22.5%) (P = 0.023). The mean angle of deviation in the primary position (PP) at distance was 21.7 ± 11.5 △ for esotropic group and 17.8 ± 12.4 △ for exotropic group. Sixty-two (9.0%) patients required second surgery for resolving residual misalignment (1.1 surgeries for each patient). CONCLUSIONS: About two-thirds of DRS patients had AHP, one-third had overshoots, and one-sixth had amblyopia. The results show that different types of DRS are associated with different epidemiological and clinical characteristics.